This Jubile Book is written by experienced clinicians and scientists in the field of sleep medicine in Belgium, and active members of the Belgian Association of Sleep Medicine and Sleep research (BASS). It provides an overview of the most pertinent activities and trends in sleep research and sleep medicine in Belgium in the past 25 years, since its founding. It focuses on the pioneers of sleep medicine in Belgium, the founders of the BASS, clinical and scientific activities, memorable meetings and activities, and finally the future of sleep medicine. The authors have tried to make a convenient whole, which reads easily and which contains anecdotes and inside information from the field. The book is written for those who are interested in sleep research and sleep medicine and for those who want to have some historical background in this field. In short, it is a must for each clinician and scientist involved in this area.